Lesson 2.1 covered water principles and how a basic understanding of the aquatic environment is critical in implementing safe and effective aquatic classes. Water principles can also be used to provide a variety of intensity options, regressions and progressions. Get to know your members and have a plan for each class you teach. When developing a class plan, utilize fitness variables to progress and modify each exercise for your participants.
Acceleration
Acceleration describes how quickly an object changes speed or direction when force is applied. The greater the applied force, the further an object will move through the water. An object with less mass will travel further than a heavier object when the same force is applied in the direction of travel.
The amount of force that a Splash participant is able to apply depends on their individual level of muscular strength and endurance, while mass is determined primarily by body weight. A more fit and strong person can apply more force than a less fit person. Additionally, a heavier class participant will have to apply more muscular force to move through the same movement choreography as an individual with less body mass.
Range of motion
Increasing movement from a smaller to a larger range of motion will help intensify the work. In a water exercise class range of motion has an increased effect on exercise intensity due to the viscosity of the water and the increased turbulence created by greater ranges of motion.
When creating exercise plans for the splashboard, be aware of the effect on range of motion in combination with both the drag created by the splashboard as it moves through the water, and the core stability challenges to participants who are attempting to ground down to the floor of the pool.
Lever length
The length of a lever affects the movement intensity or the amount of energy required for a muscle to move a body part. Longer levers may be used to progress a movement, increasing exercise intensity, while shorter levers require less muscular recruitment and are used to regress an exercise.
- It is best to use shorter levers during the Warm-up segment of class, gradually progressing to longer levers to avoid excessive stress on joints and muscles.
- Be sure to maintain a slight bend in the joints, rather than locking or hyperextending limbs to avoid joint injury and to increase muscular effort.
Buoyancy
Participants are subjected to two opposing forces during a Splash class: the downward force of gravity and the upward force of buoyancy. Individuals experience buoyancy to varying degrees due to variations in body size, lung capacity and body composition.
Buoyancy can assist or resist movement in the water, similar to the way gravity assists or resists movements in a land-based class. Since the force of buoyancy is exerted vertically upward, any movement that is performed toward the water’s surface is considered buoyancy assisted. Conversely, any downward movement toward the bottom of the pool is resisted by buoyancy. Any movement along the surface of the water is supported by buoyancy and is termed to be buoyancy supported. Exercise design tends to work against the resistance of the water, resisting buoyancy.
Turbulence and Drag
Drag and turbulence are counterproductive for swimmers, but both properties are effective tools that aquatics instructors can use to progress and regress movements in Splash classes.
Drag can be felt as the force that opposes movement in the water. Increasing the frontal surface area or the velocity of a submerged object increases drag, thereby increasing movement intensity. Movement in the water can be regressed by decreasing surface area and movement velocity.
Additional drag can be created by increasing turbulent flow in the water. In aquatic exercise, turbulence can be defined as irregular movement of the water which creates swirls and eddies. Turbulent flow increases drag, which requires the participant to increase energy expenditure.
In a Splash class, turbulent flow can be increased by working arms in opposition to the legs as in forward traveling with impeding arm movement. Turbulence is decreased by moving in ways that calm the water, such as assisting arm movements or streamlined movement with less frontal surface area, creating less drag.